Changes in lipid metabolism have been implicated in protection against infectious diseases. In the first experiment of this study, we measured clinical lipid parameters in a murine model where the unmethylated cytidin...Changes in lipid metabolism have been implicated in protection against infectious diseases. In the first experiment of this study, we measured clinical lipid parameters in a murine model where the unmethylated cytidine phosphate guanosine (CpG) oligodinucleotide (ODN1826), a Toll-like receptor 9 (TLR9) agonist was administered in combination with D-galactosamine (GalN) that caused relatively liver-specific inflammation and toxicity. In the control mice group injected with phosphate-buffered saline (PBS) (acute psychological stress model associated with blood sampling), the serum triglyceride (TG) levels showed a rapid decrease followed by a rebound at 24 h as we have recently reported. However, such a TG rebound was impaired in the CpG/GalN- and solely CpG-treated groups of mice despite an absence of liver injury based on serum alanine aminotransferase levels in the latter group. Thus, the stress-associated serum TG rebound was abrogated by the injection of a sub-hepatotoxic CpG dose. In the second experiment, we simply measured the hepatic CD36 and SACRB1 (the gene for scavenger receptor B1 (SR-B1)) transcripts after the i.p. administration of PBS, CpG or CpG/GalN. There was a remarkable elevation of hepatic CD36 transcript expression in both the CpG- and CpG/GalN-treated mice at 8 h post-CpG injection whereas the increase in the PBS-treated mice was slower than the former two groups, suggesting that hepatic CD36 transcript expression is more pronounced in the combined stress models than under psychological stress alone. The individual mice data showed that the increase in CD36 expression was accompanied by a reduction in SCARB1 mRNA, showing reciprocal regulation between these two genes. Together with our previously reported findings, these data suggest that, in a murine model combining psychological stress with TLR-triggered hepatic inflammation, the psychological stress facilitates liver uptake of plasma TG (and its components fatty acids), but the subsequent re-esterification and/or release of TG-rich lipoproteins from the liver is impaired due to the concomitant TLR-signaling. We hypothesize that lipid metabolism during acute stress shifts toward an elevated hepatic uptake of lipids due to concomitant TLR signaling, facilitating the clearance of bacterial lipids by the liver.展开更多
Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are inv...Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are involved in many biological processes and diseases playing a key role in pathogenesis,especially in multifactorial diseases such as Alzheimer’s disease.Therefore,our aim has been to provide partial insights into the interconnection between G9a,microRNAs,oxidative stress,and neuroinflammation.To better understand the biology of G9a,we compared the global microRNA expression between senescence-accelerated mouse-prone 8(SAMP8)control mice and SAMP8 treated with G9a inhibitor UNC0642.We found a downregulation of miR-128 after a G9a inhibition treatment,which interestingly binds to the 3′untranslated region(3′-UTR)of peroxisome-proliferator activator receptor γ(PPARG)mRNA.Accordingly,Pparg gene expression levels were higher in the SAMP8 group treated with G9a inhibitor than in the SAMP8 control group.We also observed modulation of oxidative stress responses might be mainly driven Pparg after G9a inhibitor.To confirm these antioxidant effects,we treated primary neuron cell cultures with hydrogen peroxide as an oxidative insult.In this setting,treatment with G9a inhibitor increases both cell survival and antioxidant enzymes.Moreover,up-regulation of PPARγby G9a inhibitor could also increase the expression of genes involved in DNA damage responses and apoptosis.In addition,we also described that the PPARγ/AMPK axis partially explains the regulation of autophagy markers expression.Finally,PPARγ/GADD45αpotentially contributes to enhancing synaptic plasticity and neurogenesis after G9a inhibition.Altogether,we propose that pharmacological inhibition of G9a leads to a neuroprotective effect that could be due,at least in part,by the modulation of PPARγ-dependent pathways by miR-128.展开更多
Toll-like receptors (TLRs) recognize specific motifs which are frequently present in bacteria, fungi, prokaryotes and viruses. Amongst TLRs, TLR9 can be activated by such bacterial or viral DNA fragments, immunoglobul...Toll-like receptors (TLRs) recognize specific motifs which are frequently present in bacteria, fungi, prokaryotes and viruses. Amongst TLRs, TLR9 can be activated by such bacterial or viral DNA fragments, immunoglobulin-DNA complexes or synthetic oligonucleotides, which all contain unmethylated cytosineguanine nucleotide sequences (CpGs). Emerging data indicate that TLR9 signaling has a role in, and may influence, colorectal carcinogenesis and colonic inflammation. CpGs are classified into three groups according to their influence on both the antigen-specific humoraland cellular immunity, and the production of type 1 interferons and proinflammatory cytokines. TLR9 activation via CpGs may serve as a new therapeutic target for several cancerous and various inflammatory conditions. Due to its probable anti-cancer effects, the application possibilities of TLR9-signaling modulation may be extremely diverse even in colorectal tumors. In this review we aimed to summarize the current knowledge about TLR-signaling in the pathogenesis and therapy of inflammatory bowel diseases and colorectal cancer. Due to the species-specific differences in TLR9 expression, however, one must be careful in translating the animal model data into the human system, because of the differences between CpG-oligodeoxynucleotide-responsive cells. TLR9 agonist DNA-based immunomodulatory sequences could also represent a promising therapeutic alternative in systemic inflammatory conditions and chronic colonic inflammations as their side effects are not significant.展开更多
The aim of the present study was to investigate the expression of toll-like receptors （TLR） 9 in peripheral blood mononuclear cells （PBMC） of patients with chronic hepatitis B and C with different virus copies. Th...The aim of the present study was to investigate the expression of toll-like receptors （TLR） 9 in peripheral blood mononuclear cells （PBMC） of patients with chronic hepatitis B and C with different virus copies. The study group included 90 patients （60 with chronic hepatitis B, and 30 with chronic hepatitis C）, and 20 healthy people served as control group. The protein and mRNA levels of TLR9 were detected by using flow cytometry and real-time PCR. The serum viral copies of HBV and HCV were measured in all patients, and the correlation between HBV-DNA copies or HCV-RNA copies and the TLR9 expression was analyzed. Our results demonstrated that HBV or HCV infection led to a decreased expression of TLR9 mRNA and protein compared to the control group （P〈0.05）. The TLR9 protein and mRNA levels were negatively correlated with serum viral copies of HBV and HCV （r=-0.632, r=-0.909, P〈0.01）. It was concluded that TLR9 mRNA and protein are down-regulated in PBMC of HBV-infected or HCV-infected patients, and they are negatively correlated with serum viral copies and play an important role in detecting viral replication of HBV and HCV.展开更多
Abnormal innate immune responses toward luminal bacteria play an important role in the pathogenesis of inflammatory bowel disease.It has been demonstrated that bacteria having CpG DNA ameliorate experimental colitis i...Abnormal innate immune responses toward luminal bacteria play an important role in the pathogenesis of inflammatory bowel disease.It has been demonstrated that bacteria having CpG DNA ameliorate experimental colitis in mice,and Toll-like receptor 9 (TLR9) signaling mediates the anti-inflammatory effects in mouse colonic inflammation.A gene variation in NOD2/CARD15 has been reported in Crohn's disease (CD) patients in Western countries,but this variation has not been identified in Japanese CD patients.Therefore,we hypothesized that TLR9 is a key factor in the development of ulcerative colitis (UC),and we investigated gene mutations and polymorphisms of TLR9 in Japanese UC patients.Three single nucleotide polymorphisms (SNPs) in TLR9 were identified in healthy controls,and were assessed in 48 UC patients and 47 healthy controls.Control subjects were matched for age,sex and date of blood sampling from among a subgroup of participants.We found that TLR9-1486CC,1174GG and 2848AA increase the risk of UC [odds ratio (OR) 2.64,95% confidence interval (95% CI):1.73-6.53,P=0.042],and TLR9-1486TT,1174AA and 2848GG decrease the risk of UC (OR 0.30,95% CI:0.10-0.94,P=0.039),although there were no correlations between SNPs and disease phenotype or TLR9 mRNA expression.These findings suggest that TLR9 polymorphisms are associated with increased susceptibility to UC.展开更多
BACKGROUND Toll-like receptors(TLRs)are the first line of host defense,and are involved in Helicobacter pylori(H.pylori)recognition and activation of both inflammatory and carcinogenic processes.The presence of single...BACKGROUND Toll-like receptors(TLRs)are the first line of host defense,and are involved in Helicobacter pylori(H.pylori)recognition and activation of both inflammatory and carcinogenic processes.The presence of single nucleotide polymorphisms(SNPs)in genes that activate the immune response may modulate the risk of precancerous lesions and gastric cancer(GC).Among them,Toll-like receptor 9(TLR9)polymorphisms have emerged with a risk factor of infectious diseases and cancer,however the studies are still inconclusive.AIM To evaluate whether TLR9 rs5743836 and rs187084 SNPs contribute to the risk of gastric carcinogenesis,and its influence on mRNA expression.METHODS A case-control study was conducted to evaluate two TLR9 SNPs(TLR9-1237 TCrs5743836 and TLR9-1486 CT-rs187084)in chronic gastritis(CG)and GC patients.A total of 609 DNA samples of peripheral blood[248 CG,161 GC,and 200 samples from healthy individuals(C)]were genotyped by polymerase chain reaction-restriction fragment length polymorphism.All samples were tested for the H.pylori infection using Hpx1 and Hpx2 primers.Quantitative polymerase chain reaction by TaqMan?assay was used to quantify TLR9 mRNA from fresh gastric tissues(48 GC,26 CG,and 14 C).RESULTS For TLR9-1237,the TC+CC or CC genotypes were associated with a higher risk of GC than C[recessive model odds ratio(OR)=5.01,95%confidence interval(CI):2.52-9.94,P<0.0001],and the CG(recessive model OR=4.63;95%CI:2.44-8.79,P<0.0001)groups.For TLR9-1486,an association between the CT+TT genotypes and increased risk of both GC(dominant model OR=2.72,95%CI:1.57-4.72,P<0.0001)and CG(dominant model OR=1.79,95%CI:1.15-2.79,P=0.0094)was observed when compared to the C group.Moreover,the presence of TLR9-1237 TC/CC+TLR9-1486 CC genotypes potentiate the risk for this neoplasm(OR=18.57;95%CI:5.06-68.15,P<0.0001).The TLR9 mRNA level was significantly higher in the GC group(RQ=9.24,P<0.0001)in relation to the CG group(RQ=1.55,P=0.0010)and normal mucosa(RQ=1.0).When the samples were grouped according to the polymorphic genotypes and the presence of H.pylori infection,an influence of TLR9-1237 TC+CC polymorphic genotypes(P=0.0083)and H.pylori infection(P<0.0001)was observed on the upregulation of mRNA expression.CONCLUSION Our findings show that TLR9 rs5743836 and rs187084 polymorphisms are associated with a higher risk of carcinogenesis gastric,and that TLR9 mRNA levels can be modulated by TLR9-1237 TC+CC variant genotypes and H.pylori infection.展开更多
Aflatoxin B_(1)(AFB_(1))is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin,particularly causing damages to kidney.Glomerular podocytes are terminally differentiated epithelial cells.AF...Aflatoxin B_(1)(AFB_(1))is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin,particularly causing damages to kidney.Glomerular podocytes are terminally differentiated epithelial cells.AFB_(1)induces podocyte inflammation,proteinuria and renal dysfunction.Studying the mechanism of AFB_(1)-induced podocyte inflammation and murine kidney dysfunction,we detected that AFB_(1)increased ubiquitindependent degradation of the transcription factor RelA through enhanced interaction of RelA with E3 ubiquitin ligase tripartite motif containing 7(TRIM7)in mouse podocyte clone-5(MPC-5)and mouse glomeruli.Reduction of RelA resulted in decreasing microRNA-9(miR-9)and activating the chemokine receptor 4(CXCR4),thioredoxin interacting protein(TXNIP),and NOD-like receptor pyrin domain-containing 3(NLRP3)signaling axis(CXCR4/TXNIP/NLRP3 pathway),leading to podocyte inflammation.We also determined that downregulation of miR-9 led to CXCR4 expression and the downstream TXNIP/NLRP3 pathway activation.Overexpression of miR-9 or deletion of CXCR4 suppressed AFB_(1)-induced CXCR4/TXNIP/NLRP3 pathway,resulting in alleviating podocyte inflammation and kidney dysfunction.Our findings indicated that ubiquitin-dependent proteolysis of RelA,downregulation of miR-9,and activation of CXCR4/TXNIP/NLRP3 pathway played an essential role in AFB_(1)-induced glomerular podocyte inflammation.Our study revealed a novel mechanism,via RelA,for the control of AFB_(1)’s nephrotoxicity,leading to an effective protection of food safety and public health.展开更多
文摘Changes in lipid metabolism have been implicated in protection against infectious diseases. In the first experiment of this study, we measured clinical lipid parameters in a murine model where the unmethylated cytidine phosphate guanosine (CpG) oligodinucleotide (ODN1826), a Toll-like receptor 9 (TLR9) agonist was administered in combination with D-galactosamine (GalN) that caused relatively liver-specific inflammation and toxicity. In the control mice group injected with phosphate-buffered saline (PBS) (acute psychological stress model associated with blood sampling), the serum triglyceride (TG) levels showed a rapid decrease followed by a rebound at 24 h as we have recently reported. However, such a TG rebound was impaired in the CpG/GalN- and solely CpG-treated groups of mice despite an absence of liver injury based on serum alanine aminotransferase levels in the latter group. Thus, the stress-associated serum TG rebound was abrogated by the injection of a sub-hepatotoxic CpG dose. In the second experiment, we simply measured the hepatic CD36 and SACRB1 (the gene for scavenger receptor B1 (SR-B1)) transcripts after the i.p. administration of PBS, CpG or CpG/GalN. There was a remarkable elevation of hepatic CD36 transcript expression in both the CpG- and CpG/GalN-treated mice at 8 h post-CpG injection whereas the increase in the PBS-treated mice was slower than the former two groups, suggesting that hepatic CD36 transcript expression is more pronounced in the combined stress models than under psychological stress alone. The individual mice data showed that the increase in CD36 expression was accompanied by a reduction in SCARB1 mRNA, showing reciprocal regulation between these two genes. Together with our previously reported findings, these data suggest that, in a murine model combining psychological stress with TLR-triggered hepatic inflammation, the psychological stress facilitates liver uptake of plasma TG (and its components fatty acids), but the subsequent re-esterification and/or release of TG-rich lipoproteins from the liver is impaired due to the concomitant TLR-signaling. We hypothesize that lipid metabolism during acute stress shifts toward an elevated hepatic uptake of lipids due to concomitant TLR signaling, facilitating the clearance of bacterial lipids by the liver.
基金supported by the Ministerio de Economía,Industria y Competitividad(Agencia Estatal de Investigación,AEI,to CGF and MP)Fondo Europeo de Desarrollo Regional(MINECO-FEDER)(PID2022-139016OA-I00,PDC2022-133441-I00,to CGF and MP),Generalitat de Catalunya(2021 SGR 00357+3 种基金to CGF and MP)co-financed by Secretaria d’Universitats i Recerca del Departament d’Empresai Coneixement de la Generalitat de Catalunya 2021(Llavor 00086,to CGF)the recipient of an Alzheimer’s Association Research Fellowship(AARF-21-848511)the Agència de Gestiód’Ajuts Universitaris i de Recerca(AGAUR)for her FI-SDUR fellowship(2021FISDU 00182).
文摘Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are involved in many biological processes and diseases playing a key role in pathogenesis,especially in multifactorial diseases such as Alzheimer’s disease.Therefore,our aim has been to provide partial insights into the interconnection between G9a,microRNAs,oxidative stress,and neuroinflammation.To better understand the biology of G9a,we compared the global microRNA expression between senescence-accelerated mouse-prone 8(SAMP8)control mice and SAMP8 treated with G9a inhibitor UNC0642.We found a downregulation of miR-128 after a G9a inhibition treatment,which interestingly binds to the 3′untranslated region(3′-UTR)of peroxisome-proliferator activator receptor γ(PPARG)mRNA.Accordingly,Pparg gene expression levels were higher in the SAMP8 group treated with G9a inhibitor than in the SAMP8 control group.We also observed modulation of oxidative stress responses might be mainly driven Pparg after G9a inhibitor.To confirm these antioxidant effects,we treated primary neuron cell cultures with hydrogen peroxide as an oxidative insult.In this setting,treatment with G9a inhibitor increases both cell survival and antioxidant enzymes.Moreover,up-regulation of PPARγby G9a inhibitor could also increase the expression of genes involved in DNA damage responses and apoptosis.In addition,we also described that the PPARγ/AMPK axis partially explains the regulation of autophagy markers expression.Finally,PPARγ/GADD45αpotentially contributes to enhancing synaptic plasticity and neurogenesis after G9a inhibition.Altogether,we propose that pharmacological inhibition of G9a leads to a neuroprotective effect that could be due,at least in part,by the modulation of PPARγ-dependent pathways by miR-128.
文摘Toll-like receptors (TLRs) recognize specific motifs which are frequently present in bacteria, fungi, prokaryotes and viruses. Amongst TLRs, TLR9 can be activated by such bacterial or viral DNA fragments, immunoglobulin-DNA complexes or synthetic oligonucleotides, which all contain unmethylated cytosineguanine nucleotide sequences (CpGs). Emerging data indicate that TLR9 signaling has a role in, and may influence, colorectal carcinogenesis and colonic inflammation. CpGs are classified into three groups according to their influence on both the antigen-specific humoraland cellular immunity, and the production of type 1 interferons and proinflammatory cytokines. TLR9 activation via CpGs may serve as a new therapeutic target for several cancerous and various inflammatory conditions. Due to its probable anti-cancer effects, the application possibilities of TLR9-signaling modulation may be extremely diverse even in colorectal tumors. In this review we aimed to summarize the current knowledge about TLR-signaling in the pathogenesis and therapy of inflammatory bowel diseases and colorectal cancer. Due to the species-specific differences in TLR9 expression, however, one must be careful in translating the animal model data into the human system, because of the differences between CpG-oligodeoxynucleotide-responsive cells. TLR9 agonist DNA-based immunomodulatory sequences could also represent a promising therapeutic alternative in systemic inflammatory conditions and chronic colonic inflammations as their side effects are not significant.
基金supported by a grant from Natural Sciences Foundation of Hubei Province, China (No. 2006ABA139)
文摘The aim of the present study was to investigate the expression of toll-like receptors （TLR） 9 in peripheral blood mononuclear cells （PBMC） of patients with chronic hepatitis B and C with different virus copies. The study group included 90 patients （60 with chronic hepatitis B, and 30 with chronic hepatitis C）, and 20 healthy people served as control group. The protein and mRNA levels of TLR9 were detected by using flow cytometry and real-time PCR. The serum viral copies of HBV and HCV were measured in all patients, and the correlation between HBV-DNA copies or HCV-RNA copies and the TLR9 expression was analyzed. Our results demonstrated that HBV or HCV infection led to a decreased expression of TLR9 mRNA and protein compared to the control group （P〈0.05）. The TLR9 protein and mRNA levels were negatively correlated with serum viral copies of HBV and HCV （r=-0.632, r=-0.909, P〈0.01）. It was concluded that TLR9 mRNA and protein are down-regulated in PBMC of HBV-infected or HCV-infected patients, and they are negatively correlated with serum viral copies and play an important role in detecting viral replication of HBV and HCV.
基金Supported by(in part)Grants from the Ministry of Education,Culture,Sports,Science and Technology,Japan(to Katakura K)
文摘Abnormal innate immune responses toward luminal bacteria play an important role in the pathogenesis of inflammatory bowel disease.It has been demonstrated that bacteria having CpG DNA ameliorate experimental colitis in mice,and Toll-like receptor 9 (TLR9) signaling mediates the anti-inflammatory effects in mouse colonic inflammation.A gene variation in NOD2/CARD15 has been reported in Crohn's disease (CD) patients in Western countries,but this variation has not been identified in Japanese CD patients.Therefore,we hypothesized that TLR9 is a key factor in the development of ulcerative colitis (UC),and we investigated gene mutations and polymorphisms of TLR9 in Japanese UC patients.Three single nucleotide polymorphisms (SNPs) in TLR9 were identified in healthy controls,and were assessed in 48 UC patients and 47 healthy controls.Control subjects were matched for age,sex and date of blood sampling from among a subgroup of participants.We found that TLR9-1486CC,1174GG and 2848AA increase the risk of UC [odds ratio (OR) 2.64,95% confidence interval (95% CI):1.73-6.53,P=0.042],and TLR9-1486TT,1174AA and 2848GG decrease the risk of UC (OR 0.30,95% CI:0.10-0.94,P=0.039),although there were no correlations between SNPs and disease phenotype or TLR9 mRNA expression.These findings suggest that TLR9 polymorphisms are associated with increased susceptibility to UC.
基金Supported by The Sao Paulo Research Foundation(FAPESP),NO.2013/14022-6 and NO.2014/17716-1
文摘BACKGROUND Toll-like receptors(TLRs)are the first line of host defense,and are involved in Helicobacter pylori(H.pylori)recognition and activation of both inflammatory and carcinogenic processes.The presence of single nucleotide polymorphisms(SNPs)in genes that activate the immune response may modulate the risk of precancerous lesions and gastric cancer(GC).Among them,Toll-like receptor 9(TLR9)polymorphisms have emerged with a risk factor of infectious diseases and cancer,however the studies are still inconclusive.AIM To evaluate whether TLR9 rs5743836 and rs187084 SNPs contribute to the risk of gastric carcinogenesis,and its influence on mRNA expression.METHODS A case-control study was conducted to evaluate two TLR9 SNPs(TLR9-1237 TCrs5743836 and TLR9-1486 CT-rs187084)in chronic gastritis(CG)and GC patients.A total of 609 DNA samples of peripheral blood[248 CG,161 GC,and 200 samples from healthy individuals(C)]were genotyped by polymerase chain reaction-restriction fragment length polymorphism.All samples were tested for the H.pylori infection using Hpx1 and Hpx2 primers.Quantitative polymerase chain reaction by TaqMan?assay was used to quantify TLR9 mRNA from fresh gastric tissues(48 GC,26 CG,and 14 C).RESULTS For TLR9-1237,the TC+CC or CC genotypes were associated with a higher risk of GC than C[recessive model odds ratio(OR)=5.01,95%confidence interval(CI):2.52-9.94,P<0.0001],and the CG(recessive model OR=4.63;95%CI:2.44-8.79,P<0.0001)groups.For TLR9-1486,an association between the CT+TT genotypes and increased risk of both GC(dominant model OR=2.72,95%CI:1.57-4.72,P<0.0001)and CG(dominant model OR=1.79,95%CI:1.15-2.79,P=0.0094)was observed when compared to the C group.Moreover,the presence of TLR9-1237 TC/CC+TLR9-1486 CC genotypes potentiate the risk for this neoplasm(OR=18.57;95%CI:5.06-68.15,P<0.0001).The TLR9 mRNA level was significantly higher in the GC group(RQ=9.24,P<0.0001)in relation to the CG group(RQ=1.55,P=0.0010)and normal mucosa(RQ=1.0).When the samples were grouped according to the polymorphic genotypes and the presence of H.pylori infection,an influence of TLR9-1237 TC+CC polymorphic genotypes(P=0.0083)and H.pylori infection(P<0.0001)was observed on the upregulation of mRNA expression.CONCLUSION Our findings show that TLR9 rs5743836 and rs187084 polymorphisms are associated with a higher risk of carcinogenesis gastric,and that TLR9 mRNA levels can be modulated by TLR9-1237 TC+CC variant genotypes and H.pylori infection.
基金funded by Suzhou Science and Technology Council(SNG201907)Universities Natural Science Foundation of Jiangsu Province(20KJB330002)+6 种基金General Program of China Postdoctoral Science Foundation(2022M711369)the Startup Funding of Soochow University,Jiangsu Province-Suzhou Science and Technology Planning Project(SL T201917)National Natural Science Foundation of China(32172922,31972741)Natural Science Foundation of Jiangsu Province of China(BK20211216,BK20221091)the Startup Funding of Hefei University of Technology(1302003712022058)China-CEEC Joint University Education Project(202010)the Excellence Project PrF UHK(2217/2022-2023)。
文摘Aflatoxin B_(1)(AFB_(1))is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin,particularly causing damages to kidney.Glomerular podocytes are terminally differentiated epithelial cells.AFB_(1)induces podocyte inflammation,proteinuria and renal dysfunction.Studying the mechanism of AFB_(1)-induced podocyte inflammation and murine kidney dysfunction,we detected that AFB_(1)increased ubiquitindependent degradation of the transcription factor RelA through enhanced interaction of RelA with E3 ubiquitin ligase tripartite motif containing 7(TRIM7)in mouse podocyte clone-5(MPC-5)and mouse glomeruli.Reduction of RelA resulted in decreasing microRNA-9(miR-9)and activating the chemokine receptor 4(CXCR4),thioredoxin interacting protein(TXNIP),and NOD-like receptor pyrin domain-containing 3(NLRP3)signaling axis(CXCR4/TXNIP/NLRP3 pathway),leading to podocyte inflammation.We also determined that downregulation of miR-9 led to CXCR4 expression and the downstream TXNIP/NLRP3 pathway activation.Overexpression of miR-9 or deletion of CXCR4 suppressed AFB_(1)-induced CXCR4/TXNIP/NLRP3 pathway,resulting in alleviating podocyte inflammation and kidney dysfunction.Our findings indicated that ubiquitin-dependent proteolysis of RelA,downregulation of miR-9,and activation of CXCR4/TXNIP/NLRP3 pathway played an essential role in AFB_(1)-induced glomerular podocyte inflammation.Our study revealed a novel mechanism,via RelA,for the control of AFB_(1)’s nephrotoxicity,leading to an effective protection of food safety and public health.
